1. Field of the Invention
This invention pertains to chemical coatings made from heat-expandable polymeric compositions, and, in particular, to such compositions as used as a component of art materials such as paints. Basic to the invention is the encapsulation in a monomer film forming agent of a volatile liquid or gas to form a polysphere which expands in the presence of heat.
2. Description of the Prior Art
This invention relates to chemical coatings made from expandable polymeric compositions which can be expanded by the introduction of heat at some suitable point in the use of the expandable polymeric compositions. The use in particular, is for art purposes by which these expandable polymeric compositions are painted, brushed, stenciled, coated, printed or sprayed in an artful manner to make or create an art form or craft in many unlimited, extensive forms of art. The final effect is realized when the art is subjected to heat in form of a lighted match, electric or gas fired oven, electric hair dryer, electric iron, steam, hot water, hot oil, or other heat source to cause the art form to expand in the desired manner. This invention in specific relates to the expandable polymeric compositions being added or incorporated into the artist material, of such liquid state, to impart the special feature of "expandable art." The invention also relates to the paints or coatings formed in accordance of this "expandable art" technology.
Expandable art has never been employed in an art form, so hence it is a new art medium that has extremely fascinating appeal for it allows for the creation of new effects. It is possible by incorporating "expandable art" into the normal or conventional paints, coatings and printing inks used by artists, craft masters, and art practitioners to add a new dimension to their works. It is to be understood here that the expandable polymeric compositions of this invention are meant only for art and decorative value, not for any utilitarian function, only for appearance effect by the unique topographic texture achieved.
It is to be further understood that the "expandable art" as provided by the expandable polymeric compositions of this invention combined into a paint, be it oil based or latex based (water system), and the skill of the artist in varying by degree the quantity of the expanding composition or agent employed create "expandable art" effects. Once the artist or practitioner is familiar with the mechanism of expandable art, he can vary to an unlimited degree the amount of expansion desired by the amount of expanding agent used and the kind of heat effect employed. This new art form is very challenging, and this makes it of value, for it requires skill, and work to become proficient in the use of expandable art. The employment of it is not limited, but expansive, and therein lies its appeal and value as a new art medium, or craft tool. Obviously, it would be beyond the ability in specifying this invention to detail in all exactness how it can be used; as with any truly valid art form it is beyond the ability of one man to cite all that can be created. However it is rather our intention to explain how the expandable art is made, and how it can be achieved.
The expansion is achieved by heating, the heat in turn causing the formation of a vapor or a gas that comes from vaporization of an encapsulated liquid, and/or decomposition of a chemical compound. These gas producing chemical compounds are incorporated in a suitable composition that must be especially designed to efficiently disperse and entrap the evolving gas or vapor so that the whole composition expands without allowing the gases or vapors to escape beyond the confines of the expanding compositions. To achieve this kind of expanding action effectively, is the very essence of this invention; for liquids that convert from a liquid to a vapor on heating are known phenomena of science, of which water and acetone are known, water being slow and requiring considerable heat to vaporize, whereas acetone is fast, requiring relatively little heat for vaporization; and chemical compounds that decompose on heat yielding as part of their decomposition products gases such as water, nitrogen and carbon dioxide, are also known, these compounds being azo compounds, sulphohydrazides, and nitroso compounds. These vapor producing or gas producing chemical compounds must be adequately dispersed in a specifically designed polymeric composition that encapsulates these gas producing compounds, so that on exposure to heat, the evolving gas does not escape, but is held sufficiently to cause effective expansion of the encapsulating polymeric composition or whatever subsequent polymeric medium, paint coating, or ink, is utilized so that the expandable polymeric composition is dispersed and admixed or incorporated.
To encapsulate the gas-producing chemicals they are formed into what is called "polyspheres". Polyspheres are formed by incorporation of the "seed" emulsion polymerization. These polyspheres assist in holding or entrapping the evolving gas upon the introduction of heat. However, it is still required that these polyspheres be dispersed further in a polymeric film forming composition which in its design furthers the confinement or non-escape of the gas during heat exposure, without first expanding the whole polymeric mass. The expandable polymeric composition does not have to be dried to help trap the gas, but upon immediate exposure to a temperature of sufficient heat to activate the gas-producing agents, the expandable polymeric composition will function while drying, i.e. if it is dried or set at a temperature that activates the expansion, the whole mass will effectively expand without collapse, or escape of gases. Hence, there is no need to be temperature conscious; any temperature of sufficient heat capacity to activate the expanding agents is sufficient. However, if one wishes to dry the expandable art medium, formed by incorporating the expandable polymeric composition, at a temperature below the decomposition temperature or activating temperature of the polyspheres this is perfectly acceptable. The expansion is then accomplished after the expandable art medium is dry, by subjecting it to a temperature sufficient in heat capacity to activate the polyspheres which encapsulate the gas-producing chemicals.